(1. 中南大學(xué) 地球科學(xué)與信息物理學(xué)院，有色金屬成礦預(yù)測教育部重點實驗室，長沙 410083；
2. 湖南有色金屬地質(zhì)勘探局，長沙 410007)
摘 要: 在對湘南中生代區(qū)域成礦構(gòu)造進行研究的過程中發(fā)現(xiàn)了熱柱三叉斷裂構(gòu)造，認(rèn)為這種構(gòu)造是燕山早期地幔對流活動在巖石圈形成的一種構(gòu)造型式。其主要證據(jù)包括：湘南有色金屬礦床呈3個不同方向的線狀分布；其交匯中心與湘南穹窿構(gòu)造中心吻合；構(gòu)造系統(tǒng)中礦床和成礦巖體具有同時性。已有花崗巖和火山巖的地質(zhì)、地球化學(xué)研究表明，燕山期華南深部存在地幔活動，這為湘南發(fā)育熱柱三叉斷裂構(gòu)造提供了深部構(gòu)造背景支持。三叉斷裂構(gòu)造型式的發(fā)現(xiàn)和認(rèn)識為湘南成礦作用和成礦規(guī)律研究提供了新的構(gòu)造模型。
關(guān)鍵字: 三叉斷裂；地幔柱；華南地區(qū)；花崗巖；成礦作用
（1. Key Laboratory of Metallogenic Prediction of Nonferrous Metals, Ministry of Education,
School of Geosciences and Info-Physics, Central South University, Changsha 410083, China;
2. Hunan Nonferrous Metal Geo-exploration Bureau, Changsha 410007, China）
Abstract:The mesozoic metallogenesis and tectonics in southern Hunan, China, were studied, and a triple junction was found. It is a tectonic pattern in lithosphere and its forming mechanism may be attributed to mantle convection in early Yanshanian. The main evidences for triple junction are shown as follows: the nonferrous metal deposits in southern Hunan distribute in line style in three directions; convergence center of distribution lines of nonferrous metal deposits coincide with the centre of southern Hunan dome; these deposits and their hosting granites in the triple junction system are isochronic. Geological and geochemical studies on the granite and volcanics indicate that there exist mantle activities in deep crust of southern China, which is a deep tectonic background support to the triple junction developed in southern Hunan. The finding and viewpoint of triple junction tectonic pattern in southern Hunan bring out a new tectonic model to discuss metallogenesis and its rules in this area.
Key words: triple junction; mantle plume; southern China; granite; metallogenesis
